1. Field of Invention
This invention relates to equipment and methods of use for repairing cracks and plugging holes in the casing of operational wells using a molten metal alloy. The intention of the present invention is to plug said holes with a surface flush to the net inside diameter of the production casing.
The particular advantage of the present invention is that it provides a completely integrated tool that performs all processing in a single pass deployment by means of industry standard wireline cable; thereby eliminating the need for workover rigs, multiple tool deployments, the installation of temporary bridge plugs and the subsequent milling or drilling out of residual alloy material. The present invention is particularly suitable for precision plugging of intended perforations which enable fluid communication between the wellbore formation and the production casing and to repair damaged casings in otherwise operational wells caused by corrosion, abrasion, earth movement, pressure bursting or other destructive factors.
It is contemplated that the present invention is advantageous for use in shutting off selected intervals in gas wells.
2. Description of Prior Art
U.S. Pat. No. 6,828,531 B2 Dec. 7, 2004 Spencer describes the use of eutectic metal sealing for oil and gas wells using an electrical resistance or inductive heating tool and forcing the molten alloy through perforations and into the formation or the well cement for the repair of a fault, but does not contemplate or claim the method or means to remotely control the dispensing of controlled amounts of alloy into the heater. The invention does not contemplate, describe nor claim a method or apparatus for use in selective plugging of perforations in producing wells. In addition, the process described by Spencer requires the separate installation setting of a temporary bridge plug and the subsequent drilling out and removal of excess solidified alloy material and the bridge plug.
U.S. Pat. No. 6,664,552 B2 Dec. 16, 2003 Spencer describes the use of eutectic metal among other various materials useful for sealing leaks within annuli of well casings of oil and gas wells using an electrical resistance or inductive heating tool. The invention describes the injection of material separately through the annulus vent tube where the material to be melted is deposited within any annulus between the production and surface casing of the well and above the well cement between the casings of interest. The invention does not contemplate the flow of melted sealing material through perforations in the casings and into the formation or the annulus.
U.S. Pat. No. 6,384,389 B1 May 7, 2002 Spencer describes the use of eutectic metal among other various materials useful for sealing leaks within annuli of well casings of oil and gas wells using an electrical resistance or inductive heating tool. The invention describes the injection of material separately through the annulus vent tube where the material to be melted is positioned within any annulus between the production and surface casing of the well and above the well cement between the casings of interest. The invention does not contemplate the flow of melted sealing material through perforations in the casings and into the formation or the annulus.
Various other processes and methods are utilized by the oil and gas industry for plugging and sealing of well casings including cements, gels and resins, a number of which are cited by the Spencer patents referenced above.